1. Field of the Invention
This invention pertains to locking of tilt and turn windows, more specifically to a movable window mounted for optional movement on alternative axis having a security lock integral with the axis selection mechanism.
2. Description of the Prior Art
There are many designs for window security locks. A lock for preventing movement of the window sash about one axis of a tilt and turn window should operate without interfering with movement of the window sash about the other axis.
One lock design has a housing externally mounted on the lower horizontal bar of the sash frame at the end that is distal from the vertical hinge axis. The housing contains a key operated bolt axle which rotates on a horizontal axis normal to the bar. In the locked position a finger at the end of the bolt axle is turned downward whereby it slips into an upward open slot in the bottom horizontal bar of the window frame. In the unlocked position, the finger is rotated out of the slot to the horizontal within the horizontal sash frame bar.
In the locked position, the finger in the slot prevents the sash from rotating on the window vertical axis out of the window frame. In order to be able to tilt the sash on the window horizontal axis, the lock must be unlocked unless in order to be able to tilt the sash with the lock locked the bolt finger and slot are mounted close to the window horizontal axis at the bottom of the sash about which the sash tilts, the slot is made wide enough in the direction of the bolt axle axis compared to the axial thickness of the finger to allow the sash to tilt on the window horizontal axis while the bolt is in the locked position. Then, with rotation of the lower bar of the sash, the bolt tilts in the slot and may also be partially withdrawn from the slot as it moves on the arc of sash rotation.
U.S. Pat. No. 4,624,075 patented Nov. 25, 1986 by D. Vigreux describes a turn, tilt window having a drive train control rod in the sash frame which by linear movement over three discrete distances driven by a three-position handle switches the sash from lockdown in the window frame to rotation on a vertical axis to rotation on a horizontal axis, in which the alignment position one of a lock and keeper mounted on the control rod so that it moves with the rod to engage the other of the lock and keeper on the window frame can be changed by moving the lock or keeper from a first position to a second linearly displaced mount position.
U.S. Pat. No. 3,911,621 patented Oct. 14, 1975 by M. P. McHeffey describes a tilt and turn window having a drive train around three sides of the sash. The drive train is moved linearly by a three-position handle to switch the sash from lockdown in the window frame to rotation out of the window frame on a vertical axis to rotation out of the window frame on a horizontal axis.
When the handle is moved upwardly from center position the drive train is moved counterclockwise setting the window sash for rotation or tilt out of the window frame on the horizontal axis and moving a finger behind a keeper attached to an outer vertical member of the window frame to prevent rotation of the sash out of the window frame on the vertical axis. When the handle is moved downward from the center position, the train moves clockwise setting the window sash for rotation out of the window frame on the vertical axis.
A key operated lock mechanism having a finger that is rotated by the key is installed just past the clockwise end of the drive train and positioned so that the finger can be turned linear with the drive train so that it occupies the most clockwise position of the end of the drive train that sets the window sash for rotation on the vertical axis, thereby preventing rotation on the vertical axis. Tilt on the horizontal axis is unaffected because the drive train moves counterclockwise away from the lock for that mode. The finger can be turned normal to linear motion of the drive train to allow rotation of the sash on the vertical axis.
U.S. Pat. No. 4,074,462 patented Feb. 21, 1978 by M. P. McHeffey describes a tilt and turn window having a drive train similar to the one described in his U.S. Pat. No. 3,911,621 having a key operated mechanism is at the end of the drive train, but in which the key operated mechanism mounted on the frame of the sash extends a bolt into a longitudinal slot located in the drive train so that one end of the slot coming against the bolt prevents sufficient linear movement of the drive train to set the window sash for rotation out of the window frame on the vertical axis. The slot is long enough to permit linear movement of the drive train in the opposite direction to set the sash for tilt or rotation on the horizontal axis. Drawing the bolt back with the key permits linear movement of the drive train to set the window sash for rotation on the vertical axis.